[Leetcode] [Java] Symmetric Tree

Title:

Given a binary tree, check whether it is a mirror of the itself (ie, symmetric around its center).

For example, this binary tree is symmetric:

    1   /   2   2/\/3  4 4  3

But the following are not:

    1   /   2   2   \      3    3

Test Instructions:

Given a binary tree, determine whether it is an image of itself (i.e., the center symmetry about it)

For example, the following lesson the binary tree is symmetrical:

    1   /   2   2/\/3  4 4  3

but the following is not:

    1   /   2   2   \      3    3

Algorithm Analysis:

By recursion, the left and right nodes of the node are determined to be equal.

AC Code:

<span style= "Font-family:microsoft yahei;font-size:12px;" >public class Solution{Public    Boolean issymmetric (TreeNode root)     {         if (root==null) return true;         Return Issym (root.left,root.right);    }    public boolean issym (TreeNode Left,treenode right)    {    if (left==null && right==null) return true;    if (left!=null && right==null) return false;    if (left==null && right!=null) return false;    if (Left.val!=right.val) return false;    else return Issym (left.right,right.left) &&issym (left.left,right.right);}    } </span>

Copyright NOTICE: This article is the original article of Bo Master, reprint annotated source

[Leetcode] [Java] Symmetric Tree